Illumination system and exposure apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorToshihiko Tsuji
Life of this patent
Estimating the term…
Abstract
An illumination system includes a first optical integrator of inside reflection type, for reflecting at least a portion of received light, with its inside surface, and for defining a surface light source at or adjacent a light exit surface thereof, a second optical integrator of wavefront division type, for dividing the wavefront of received light and for defining a plurality of light sources at or adjacent a light exit surface thereof, an imaging optical system for imaging the surface light source at or adjacent a light entrance surface of the second optical integrator, and a collecting optical system for superposing light rays from the plurality of light sources one upon another, on a surface to be illuminated, wherein the imaging optical system has a variable imaging magnification.
Claims22
An illumination system, comprising:
- a first optical integrator of inside reflection type, for reflecting at least a portion of received light, with its inside surface, and for defining a surface light source at or adjacent a light exit surface thereof;
- a second optical integrator of wavefront division type, for dividing the wavefront of received light and for defining a plurality of light sources at or adjacent a light exit surface thereof;
- an imaging optical system for imaging the surface light source at or adjacent a light entrance surface of said second optical integrator;
- and
- a collecting optical system for superposing light rays from said plurality of light sources one upon another, on a surface to be illuminated;
- wherein said imaging optical system has a variable imaging magnification.
An illumination system, comprising:
- a wavefront division type optical integrator for dividing the wavefront of received light and for defining a plurality of light sources at or adjacent a light exit surface thereof;
- a light projecting optical system of variable focal length, for projecting light from a light source to a light entrance surface of said wavefront division type optical integrator, wherein a change in focal length of said light projecting optical system causes a change of at least one of the size and the intensity distribution of the light, from the light source, upon the light entrance surface of said wavefront division type optical integrator;
- a collecting optical system for superposing light rays from said plurality of light sources one upon another, on a surface to be illuminated;
- wherein said light projection optical system serves to correct a numerical aperture of light, impinging on said wavefront division type optical integrator, as changed by the change in focal length.
An illumination system, comprising:
- a first optical integrator of wavefront division type, for dividing the wavefront of received light and for defining a plurality of light sources at or adjacent a light exit surface thereof;
- a second optical integrator of inside reflection type, for reflecting at least a portion of received light, with its inside surface, and for defining a surface light source of uniform intensity distribution, at or adjacent a light exit surface thereof;
- a third optical integrator of wavefront division type, for dividing the wavefront of received light and for defining a plurality of light sources at or adjacent a light exit surface thereof;
- a first imaging optical system for imaging the light sources as defined by said first optical integrator, on or adjacent a light entrance surface of said second optical integrator;
- a second imaging optical system for imaging the surface light source as defined by said second optical integrator, on or adjacent a light entrance surface of said third optical integrator;
- and
- a collecting optical system for superposing light rays from the light sources as defined by said third optical integrator, one upon another on a surface to be illuminated.
Dependencies are inferred from the claim text.